PET amyloid ligand [11C]PIB uptake and cerebrospinal fluid beta-amyloid in mild cognitive impairment.
BACKGROUND
In mild cognitive impairment (MCI), Alzheimer's disease (AD)-type cerebrospinal fluid (CSF) biomarker profiles predict rapid progression and conversion to AD. An increased brain amyloid burden in AD and MCI has been demonstrated with PET using [(11)C]PIB (Pittsburgh compound B). Little is known about the relationship between these biomarkers in MCI.


METHODS
We studied 15 patients with amnestic MCI and 22 controls with PET using [(11)C]PIB. In MCI patients, CSF levels of Abeta42, pTAU, totalTAU and the Abeta42/pTAU ratio were measured.


RESULTS
In MCI patients, CSF Abeta42 was abnormal in 53% of patients, totalTAU in 67%, pTAU in 64% and the Abeta42/pTAU ratio in 64%. A composite neocortical [(11)C]PIB uptake score was increased in 87% of the MCI patients. Only 54% of [(11)C]PIB-positive subjects showed AD-type Abeta42 values. During a 2-year follow-up, 6 MCI patients converted to AD, all of them had increased neocortical PIB scores at the MCI stage. Abnormal CSF Abeta42 was found in 3 patients, pTAU in 3 patients and Abeta42/pTAU ratio in 4 patients.


CONCLUSIONS
Follow-up studies are needed to confirm whether [(11)C]PIB uptake might be more sensitive than CSF Abeta42 concentration in detecting increased amyloid burden in MCI, as suggested by the results of this study.
Koivunen
J
J
Turku PET Centre, University of Turku, Turku, Finland.
Pirttilä
T
T
Kemppainen
N
N
Aalto
S
S
Herukka
S-K
SK
Jauhianen
A M
AM
Hänninen
T
T
Hallikainen
M
M
Någren
K
K
Rinne
J O
JO
Soininen
H
H
D000368:Aged; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D000814:Aniline Compounds; D052160:Benzothiazoles; D015415:Biomarkers; D003072:Cognition Disorders / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008024:Ligands; D008297:Male; D019579:Neocortex / Q000000981:diagnostic imaging / Q000378:metabolism; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D049268:Positron-Emission Tomography; D012372:ROC Curve; D019275:Radiopharmaceuticals; D013844:Thiazoles; D016875:tau Proteins / Q000134:cerebrospinal fluid
C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D052160:Benzothiazoles; D015415:Biomarkers; D008024:Ligands; D010446:Peptide Fragments; D019275:Radiopharmaceuticals; D013844:Thiazoles; C075222:amyloid beta-protein (1-42); D016875:tau Proteins